anton i



G. AND U. ANTONI.

FLEXIBLE RIB FRAME FOR AEROPLANE WINGS.

APPLICATION FILED MAY 6, IBIS.

Patented Dec. 2, 1919.

2 SHEETS-SHEET I.

Inventors cal/W02 Attorngys G. AND U. -ANT0N|.- FLEXIBLE RIB FRAME FOR AEROPLANE WINGS.

APPLICATION HLED MAY 6. 1916.

1,323,385; Pate ted 1)e@. 2, 1919.

f 2 SHEETS-SHEET 2.

GUIDO ANTONI AND UGO ANTONI, OF PISA, ITALY.

FLEXIBLE-RIB FRAIME FOR AEROPLANE-WINGS.

Specification of Letters Patent.

Patented nee. 2, 1919.

Applicationfiled May 6, 1916. Serial 11:0 95,917.

To all whom it may concern:

Be it known that we, Ginno ANTONI, draftsman, and Uoo ANTONI, employee, subjects of the King of Italy, residents of Pisa, in the'Kingdom of Italy, No. 1 Via Cappuccini, have invented new and useful Improvements in Flexible-Rib Frames for Aeroplane-Wings, of which the following is a specification.

' The object of the present invention is a frame with flexible ribs for aeroplane wings enabling the alteration of the curvature of the supporting surfaces through contraction of the frame without setting up strains dangerous to the stability of the flying machine or to the deformability of its parts, and without substantially altering the nature or form of the curvature although its pitch is varied.

The annexed drawings show, by way of example, one embodiment of the invention. Figure 1 is a longitudinal section of the wing frame and shows in dotted lines the contracted curvature (with the convexity turned upward) that the flexible rib can as- SllIIlG.

Fig. 2 shows a rib for the so called wings equilibrium zone where as indicated in dotted lines, the curvature assumed through contraction. has a convexity turned downward.

Fig. 3 shows a rib element or spar in plan.

' Fig. 4: shows the same rib element in elevation.

Fig.5 shows to a larger scale two portions of the rib, viz., the front portion and the portion connected to the second cross girder.

Fig. 6 is a plan showing the portion of the rigid-frame comprised between the two rigid cross girders, relatively to which girders the flexible longitudinal ribs can be deformed.

Fig. 7 shows a cross girder portion fitted with a plate for distributing the stresses set free or rear ends of the ribs is required while the ribs S (Fig. 2) are used in'the zone where an upward movement of the free ends of the ribs is required. In both cases the ribs consist of an upper spar aand a lower spar b (respectively a'-- and b'-) held invariably apart at their front ends by a spacing piece o which may be provided with lightening holes, and one or both of the spars m. and -b are capable, of sliding in stirrup shaped brackets -d secured to the center cross girder .-Z (Fig. 5). thickness of the spars w and -b, starting from the supportin point A on the center cross girder, tapers th toward the front end C and the rear end B. In the rib k (Fig. 2) the spar thickness remains con-' stant from A to the front end C and tapers from A to the rear end B. Figs. 3 and 4 show in plan and elevation respectively a spar with uniform breadth and tapering thickness. The front portion of the rib is stiffened by means of iron straps h wound around it and riveted either to the spar or to distance pieces forcedbetween the strap windings and the side wall .c. The rib S or S is hinged to the front cross girder -Z to this end (see Fig. a window e is formed in the front portion of the rib and, as may be seen from the figure, the bottom portion of the left hand window-side is curved forward while the top portion of the right hand window-side is curved backward so as to increase the window width accordingly and to allow the rib to pivot on the I the rib s (Fig. 1 the cross girder Z (the opposite sides of which are made slightly convex) from the position shown in full lines to that shown in dotted lines on operation of the corresponding control by the pilot. The top and bottom window-sides also are curved, the convex face of the curve being turned inwardly. Angle pieces screwed to the cross girder alone are provided to prevent the rib from moving laterally with respect to the window -e.

Due to the construction just described the rib S (Fig. 1), on operation of the corresponding control by the pilot, can be contracted in the portion comprised between the front cross girder Z..v and the central cross girder -l (Fig. 5), the rib still passing through the middle points of the cross sections of the said cross girders; in order to facilitate this, the spars are made capable of sliding in the brackets -d.

Figs. 1 and 2 show in dotted lilies the pro file which can be assumed by the ribs S and S respectively. By this arrangement, while the pitch or sag of the rib curve is varied, the nature and shape of the curve are not considerably altered.

As the front and central cross girders are not rigidly connected by the ribs, in order to enable the ribs to shift their position when the curve is altered, provision must be made to make the system of the two cross girders rigid. This is achieved by means of stays 2' rigidly secured to the cross girders by angle plates r-, these angle plates in their turn being secured in place with screws; one of these screws is an-eye-scrcw and serves for attachment of the bracing wires.

In correspondence to the connections of the stays i with the cross girders -Z., and Z.,- specially shaped plates p are provided, the object of which is to distribute over a larger cross girder area any stresses set up by the wing suspension wires. The plates p are straddled over the cross girder and have a tail piece gat the top and two extensions 8 at the bottom for attachment of the tensioning wires.

Having now described our invention and how the same is to be carried out, what we claim as our invention, is:

1. In an aeroplane wing, the combination with a rigid central cross-girder, a rigid front cross-girder and a rear cross-girder, of ribs comprising spars having a uniform width and a thickness tapering from the middle to both ends thereof, a pivotal connection between the rib and the said front girder and a sliding connection between the rib and the said central girder.

2. In an aeroplane wing, the combination with a rigid front cross-girder, a rigid central cross-girder and a rear cross-girder, of a rib comprising spars having a uniform width and a thickness tapering from the middle to one end thereof, a pivotal con-' nection between the rib and-the said front girder and a sliding connection between the rib and the said central girder.

3. In an aeroplane'wing, the combination with a rigid front cross-girder, a rigid'eentral cross-girder and a rear cross-girder, of ribs comprising an upper and a lower spar having a uniform width and a thickness tapering from the middle to both ends thereof, a stiffening web connecting the upper and lower spars with one another at their front ends, said web having an opening fitting said front girder, the curved sides of said opening being arranged with their convexity directed inwardly, angle pieces on said front girder to prevent any lateral displacement of said rib, and brackets on said central girder slidingly engaged by said spars.

4. In an aeroplane wing, the combination with a rigid front cross-girder, a rigid central cross-girder and a rear cross-girder, of ribs comprising spars having a uniform width and a thickness tapering from the middle to both ends thereof, a pivotal connection between said rib and front girder, a sliding connection between said rib and central girder, stays extending between and at right angles to said front and central girders and rigidly secured thereto, and diagonal bracing wires stretched between said front and central girders.

5. In an aeroplane wing, the combination with a rigid front cross-girder, a rigid central cross-girder and a rear cross-girder, of ribs comprising spars having a uniform width and a thickness tapering from the middle to both ends thereof, a pivotal con nection between said rib and front girder, a sliding connection between said rib and central girder, stays extending between and at right angles to said front and central girders and rigidly secured thereto, diagonal bracing wires StI'BlJClIGClabEtWBGH said front and central girders, and stress distributing plates straddling the portions of said front and central girders adjacent said stays and provided with means for attachmentv of the wing tensioning wires and bracing wires.

In testimony whereof we hereunto afiix our signatures in the presence of two wit- GUIDO ANTONI. UGO ANTONI.

nesses.

Witnesses GINO SORILLINO, ANTONIO MAINAND. 

